Endoscopic endonasal approach to the middle and upper clivus. The meningeal dural layer has been removed bilaterally to expose the intradural structures. The intradural segment of the abducens nerve can be identified running superiorly to continue as the interdural segment. In the upper clival region, we can identify the basilar bifurcation, SCA, PCA, and oculomotor nerve. (Image courtesy of JC Fernandez-Miranda)